Nice historical overview of communicable diseases.
Pay particular attention to the time between pandemics.
Almost every disease originated from animals. So-called zoonoses. Think SARS, MERS, Ebola, AIDS, swine and bird flu etc.
We owe this to our intensive livestock farming and in the Far East the overcrowded animal markets.
These are literally hothouses for new diseases from which zoonoses arise (diseases that are transmissible to humans)
As long as we keep many creatures in a small space, there will be relatively more chance of diseases that are a big risk. So our own lifestyle is also part of that risk.
As can be seen, there have been 5 dangerous disease outbreaks in the last 20 years, as opposed to the roughly 1 disease per max 50 years before (also mainly zoonoses)
This is important to think about. Do we really want to continue to treat animals this way and eat meat when these are the risks?